Electrical socket



Dec. 29, 1931. H. SHAPIRO ELECTRICAL SOCKET Filed Feb. 6, 1925 ILIVENTORY M W yman J'apzka M ATTORNEYS Patented Dec. 29, 1931 UNITED STATESPATENT OFFICE HYMAN SHAPIRO, or NEW YORK, N. Y; ASsIeNoR. BY MESNEASSIGNMENTS, TO THE M. PROP? (:0. INC., on NEW YORK, N. Y., AconronA'rroN on NEW YORK ELECTRICAL SOCKET Application filed February 6,1925. Serial No. 7,207.

.; ceived in a wall socket or any appropriate outlet socket.

Among the objects of the invention are to provide a Simple and ruggedsocket construction, the constituent parts of which are easily producedat small expense and easily assembled. Another object is' to provideselectively operating switch means of simple construction, free fromdanger of arcing or of short circuit, and more especially to embody such3.} switches in a Socket of the type mentioned.

Preferably the socket includes a mating pair of complementary members ofmolded insulating material, coacting to define the sockets and toprovide a mounting for switching mechanism and terminal contacts, saidsections and their associated parts being assembled by unskilledoperatives.

I contemplate the use of a pull chain type of switches for eitherindependently or simultancously controlling both circuits and foroptionally closing either circuit and opening the other circuit.

In accordance with a specific embodiment of the invention, I prefer toattach the metal- 31) lic shell which encircles the plug of the duplexsocket member in a manner which involves no threaded connections betweenthe shell and the socket. This is preferably accomplished by making theplug of the socket member of non-circular shape and providing thecircular eXteriorly threaded shell with an inwardly projecting flangeportion fitting the plug.

Another feature of the invention resides in the manner in which thecontact terminals house and retain the metallic strips which constitutethe electrical terminals, thereby obviating the necessity for usingrivets, screws or other conventional types of securing devices. a

Another feature of the invention resides in the provision of. matingrecesses in the opposed faces of the molded sections for snuglyaccommodating and housing of the operating parts of the switchingmechanism.

Another feature is the provision of encircling bands around the mouthsof the sockets for greater security of the assembly of the mating moldedsections.

In the accompanying drawings, in which are shown one of the variouspossible illustrative embodiments of this invention,

Figure 1 is a plan view of a completely assembled socket; A

Figure 2 is a transverse Sectional view on i the line 22 of Figure 1,showing one section of the socket and pull chain switching mechanismmounted therein.

Fig. 2a is a detail on line H of Figure 2; Figure 3 is an enlargedfragmetary detail on the line 33 of Figure 2;

Figured is a bottom plan view of the exteriorly threaded cap whichassists in holding the sections of the socket in assembled relationshipFigure 5 is an enlarged sectional detail of the ratchet wheel whichforms part of the switching mechanism. 1

Referring to Figures 1 to 5, the socket comprises two mating moldedinsulating sections 15 and 16, each including an intermediate bodyportion 17 of substantial solidity and on opposite sides of suchintermediate portion a pair of short arms hollowed out to provideinternally threaded socket portions 18, 18, disposed approximately atright angles to each other. Forming a continuation of the body portionof each member is a plug portion 19 cut away internally as indicated at20 to accommodate the switching mechanism. When the two Sections 15, 16

are placed together in mating relationship, the two hollow neck portionscooperate to provide a plug of oval exterior shape upon which fits anexteriorly threaded shell 21 provided with an inwardly turned flange 22having an oval opening therein to prevent rotation of the shell on theneck of the socket. By virtue of this construction, I am able toeliminate the necessity for exteriorly threading the socket neck andsimply slip the shell in place and hold it against rotation on the neck,by the non-circular flange 22. Suitable supplemental means may beprovided for anchoring the shell. 21 against rotation relative to theneck of the socket member such for instance as inwardly turned tongues23 engaging in corresponding notches 24: in the neck or by soldering theshell 21 to the terminal contact pieces 25 which form part of theswitching mechanism or by swaging the lowermost edge of shell 21 inward.

As an additional precaution against the accidental separation orrelative displacement of the two mating sections 15 and 16, I preferablyemploy annular metallic bands 50 encircling the extremities of the shortarm portions thereof, said bands being frictionally fitted or otherwisefirmly, but preferably detachably, secured in place. The two sections ofthe duplex sockets are thus secured together at their three outermostparts and are accurately maintained in proper mating relationship.

It will be understood that the shell portion 21 is screwed into asuitable outlet plug in the wall, or in the socket ofan ordinary electric light fixture, and the sockets 18 receive electric bulbs orconnections for other elec trical apparatus. I equip the sockets 18 withcontact members to engage the said shell and the central terminalcontact of an electrio lamp having the ordinary Edison base. lVith theform of invention shown in Figures 1 to 5, the switching mechanism. forthe two sockets 18, 18 are entirely independent of each other andpreferably control current to the lamps through the medium of contactarms 25 leading from plug shell 21 to the centers of the sockets. Thelamp circuit from terminal contact finger 28 is completed through theside of the socket 18 by stationary fingers 45 disposed in grooves inthe sock ets and waved in conformity with the interior socket thread.One of these arms is integral with, and the other connected to a centralarm 46 retained by and housed in a pair of cooperating grooves a7running centrally through the supplementary members 15, 16 of the duplexsocket. The latter conducting member 46 terminates at its outer end in aspring tongue 48 adapted to engage the base of the socket (not shown)into which plug shell 21 is screwed. It will thus be seen that the shell21 is electrically con-- nected to the fingers 28 in the base of sockets18 and that tongue 48 is electrically connected to the fingers 15 in thesides of the sockets 18.

Arms 25 are preferably made in two separate sections one sectionprojecting through the molding 15 and being soldered as at 26 to theinterior of the lower ends of the shell 21. The other terminal sections2565 of the arms are secured as at 27 to the molding 15 and terminateeach in spring linger 28 projecting into the base of the correspondingsocket 18 and adapted to make contact with terminals on the bases oflamps (not shown). The two sections of the current carrying arms areadapted to be electrically connected by switch arms 30, the latter beingfixed to ratchet wheels 31 journ aled on studs 32 in the recess 20between the adjacent ends of the two sec tions 25, 25a. Preferably therecess 20 is of sulficient depth to conveniently and snugly accommodatethe ratchet wheel and the switch arm 30 which it carries, withoutpermit-ting any substantial lateral play thereof along the stud uponwhich it is journaled. "hus, there will be no tendency for the ratchetwheel to rattle or shift its position other than rotationally after thesocket is assembled and the ratchet wheel is turned in the ordinarycourse of use. This construction appears most clearly in Figures 3 and 5and it will be noted that the advancing corners of the switch arms 30are up turned as indicated at 33 to provide cam surfaces which will rideover steps 34 and over the upturned corner 35, of section 25 of theswitch arm. The pawl mechanism for operating the ra het wheels is shownas com.- pris ng pull chains 36, consisting of a series of flexiblyconnected balls spaced apart a distance approximately equal to thedistance between the teeth of the ratchet wheels 31. The ends of pullchains 36 are yieldingly anchored within the hollow neck 19 by securingthem to stop pieces 37 at the free ends of springs 38 anchored at 39within the nerk. Chains 36 are led over the teeth of the ratchet wheelsand to the exterior of socket member 15, 16 through openings 40, and,when the chains are pulled to effect rotation of the ratchet wheels, thestops 37 engage against stop pins 41 to limit the extent to which thechains may be pulled. These stop pins not only prevent overthrowing ofthe ratchet wheels and consequent movement of the switch arm 30 from oneopen to the other open position or from one closed to the oppositeclosed position but they also considerably prolong the life of springs38 by making it impossible to stretch the latter beyond their elasticlimit. Upon each downward movement of a chain 36, its associated switcharm 30 will move a little more than 90, one o f the following corners33a thereof snapping back against either the corner or stop pin 34 asthe spring exerts its influence when the chain is released.

It will be understoodthatfwhile I- shown switchingmechanismindependently controlling each of the sockets118 and operableto electrically disconnectthe era 28 and the shell '21, asingleswitchmi'ght: used to simultaneously control the lamps in both sockets18 and such switching mechanism might be associated with the stationarycon- 256; would consist each'of a single length of metal instead ofapair of separated sections.

It is also to be noted that while each chain itself is the preferredpawl mechanism'itoroperating the corresponding ratchet wheel, vari-ousexpedients other than those shown might be-rcsorted to for operating andlimiting the throw of the ratchet when the chain is pulled and forpreventing overtaxing the strength of'the springs 38 In the embodimentof Figure 2, the projecting spring end'48 of the central plug contact isnot lilrely to bestrained, or to break at the hinge line when pressedinto theoutlet socket since the length of spring metal in- 5 tegraltherewithand longitudinal of'the plug is free to flex within the hollowstructure of the plug thereby permitting such: accommo dation withoutstrain, and affording effective spring contact engagement in the outletsocket. g

While I have shown duplex'socket embodying in detail the construction ofa'pull chain type of switch, it will be understood that various othermethods of securing the complementary socket sections together may beemployed; butthe method shown in the drawings and described above isseen to greatly expedite assembling the device that it obviates thenecessity of exteriorly T threading the plugs of the sockets -o r accurately fitting the shells on the plug portions. The current carryingmembers orconducting arms are accommodated in complementary groovesformed. in the complementary sec tions of the duplex socket, that is tosay, the

current carrying arms 25, fingers 4:5 and cen tral. arm 46 are simplylaid 1n place in their respective grooves when the two sections of g thesocket areasse mbled and require use'o f no securing device, such asscrews, rivets,-o r the like. i

It will thus be seen that there is herein de scribed apparatus in whichthe several features of this invention are embodied, and which apparatusin its action attains the various objects of the invention and iswellsuited tomect the requirements of practical use. I

As many changes could be made inthe above construction and manyapparently widely different embodimentsofthis invention could be madewithout departing from the scope thereof, it is intendedth-at all-mattercontained in the above description or shown in the accompanying drawingsshall be members i illustrative and not in a limit- :ing sense.- Forinstance, the duplexsocket is only-onefform .of cluster fixture to whichmany features of the invention are applicable..

-Havingthus described my invention what 'l c'lai m as new and desiretosecure by Letv *te rs Patent is": ducting arm 46 in which caseconductn rs 25. J

1; A duplex socket including "a pair of complementary members of moldedinsulating material cooperating to provide a body portion, .a plugportion, and diverging arm portions, the latter having sockets complete--ly housed therein, a thinband encircling the outer. surface only ofsaid arm portions to retain the members together, and a threaded shellaround theplug portion having nonthneaded' engagement with the latterand assisting. in retaining the complementary members of th'e socketagainst accidental separation, said plug portion being ofnonci'mulareirternal shape and said shell being non-rotatablyengagedtherewith.

- '2. ..A duplexsocket including a pair of complementary sectionsofmolded insulating material cooperating to provide a body portion, aipairiof short divergingarm portions hav- :ing sockets therein and aplug portion adapted to beinserted-in an outlet socket, said plugportion having a threaded she'll about the same for insertioninto asocket, said plug having a'substantially oval exterior shape, and saidshell havingfan inturned flange ad-aptedto contact the exterior surfaceof said plugto prevent rotation of said shell. 3. A duplex socket.including a pair of complementary sections of molded insulating-materialcooperating to provide a body portion, a 'pairof'short diverging armportions havingsockets therein and a plug portionadaptedtoib'e insertedin an outlet socket, said-rlplug portion having a threaded shell aboutthe 'same. for insertion into a socket, said plug having a.substantially oval exterior shape, saidshell having an inturnecl flangeadaptedto contact the exterior surface bf said plug toprevent rdtationof said shell, contact members "soldered to the shell andprojcctingcinto the bases of the socket and contact members disposed inthe sides of the sockets and electrically connected to a spring tongueprojecting through the plug portion of the socketout of contact with theshell.

4; A duplex-socket including a pair of complementary'sections of moldedinsulating:ma/cerial:cooperating to provide a body portion, apair ofshort diverging arm portions having sockets, therein and a plug portionadapted to be inserted inan outlet socket, said plug-portion having athreaded shell about-the same for insertion into a socket,

contact members soldered to the shell and projecting into the bases ofthe sockets, and contact members disposed in the sides of the sockets,and electrically connected to a spring tongue project-ing through theplug portion of the socket out of contact with the shell,

said contact members comprising strips of conducting material housed incooperating grooves in the two sections of the duplex socket.

5. A duplex socket including a pair of complementary sections of moldedinsulating material cooperating to provide a pair of sockets, electricalconducting devices projecting into the bases of the sockets, electricalconducting devices projecting into the sides of the sockets, saidconducting devices including strips of conducting material housed withinand retained by cooperating grooves in the mating faces of thecomplementary sections, said sections cooperating to provide a plugportion adapted to be inserted in an outlet socket and a conductingshell around said plug portion, said plug being oval shaped, said shellhaving an oval portion for holding the complementary members incooperating relationship and electrically connected to the conductingdevices which project into the bases of the sockets, and a spring tongueprojecting from the end of said plug portion insulated from said shelland electrically con nected to the conducting devices disposed in thesides of said sockets.

6. A duplex socket member including a pair of complementary sections ofmolded insulating material retained in mating rela tionship andco-operating to provide a pair of sockets and switching mechanism housedin the duplex member and operable to selectively control the circuits ofthe sockets, said switching mechanism including a pair of ratchet wheelsmounted on parallel shafts, a pair of oppositely extending switch armscarried by each of the ratchet wheels, pull chains co-operating directlywith the teeth of the ratchet wheels to swing the switch arms, and apair of spaced contacts adapted to be engaged by each pair of arms forcompleting the circuit for each socket.

7. A pull chain switch including a ratchet wheel, a switch arm carriedby the ratchet wheel, a pull chain having its links engaged with theteeth of the ratchet wheel to effect turning movement thereof in onedirection, and a contact member adapted to engage said switch arm, saidarm and member having cooperating means to prevent reverse movement ofsaid ratchet wheel.

8. An electrical attachment member including a pair of complementarymating sections of molded insulating material co-operating to provide atleast one socket, spaced terminal contact members for the socket housedin co-operating grooves in the mating faces of the sections, switchingmechanism controlling the flow of current to said terminal contactmembers and housed in mating recesses in the opposed surfaces of thesections, said switching mechanism including a rotatable member mountedon a shaft attached to one of said sections and disposed between saidcontact members, a pair of oppositely disposed switching arms carried bysaid rotatable member and adapted to connect in circuit with theterminal contact members, and pull chain operating means having itslinks directly connected to said rotatable member.

9. A pull chain switch including a ratchet wheel, diametrically disposedswitch arms mounted on said wheel, diametrically opposed spacedstationary contact members adapted to engage said arms, a pull chainhaving its links directly engaged with the teeth of the ratchet wheelfor rotating the same, a spring anchoring the pull chain for retrievingthe chain when the chain is released, means for positively limitingmovement of said chain when the same is pulled and interengaging meansassociated with said contact members and switch arms to prevent areverse movement of said wheel when said chain is released after beingpulled.

10. A pull chain switch including a ratchet wheel, diametricallydisposed switch arms mounted on said wheel, diametrically opposedstationary contact members adaptcd to engage said arms, a pull chainhaving its links directly engaging with the teeth of the ratchet wheelfor rotating the same, a spring anchoring the pull chain adapted to betensioned upon pulling the chain and retrieve the chain releasing thesame, means for positively limiting the pulling movement of the chain torotate said wheel somewhat more than 90 each time the chain is pulled, astop over which the switch arms is adapted to ratchet and which limitsretrograde movement of the switch arms to a position spaced 90 from saidcontact members, said contact members and switch arms being providedwith interengaging means adapted to prevent retrograde movement of saidwheel whereby the switch arms will always come to rest under theinfluence of the spring when the chain is pulled the full distancedetermined by the limiting means in either full open or full closedposition.

11. A duplex socket member including a pair of similar complementarysections of molded insulating material having cooperating recesses intheir mating faces providing a pair of sockets and having cooperatinggrooves in their mating faces adapted to receive and house terminalcontact members for said sockets, said sections having inde pendentswitching mechanism for each of the sockets housed in recessescommunicating with the mating faces of the sockets, said switchingmechanism including aligned ratchet wheels of a thickness approximatelyequal to the width of the recesses, switch arms carried by the ratchetwheels and pull chains having their links directly engaged with theteeth of the ratchet wheels to efiect movement thereof, said contactmembers beiniadapted to engage the switch arms of each w eel uponmovement of said ratchet wheels for completing the circuit for saidsockets.

m Signed at New York in the county of New York and State of New York,this 29th day of January, A. D. 1925.

HYMAN SHAPIRO.

